The sputtering process or other deposition process that is performed in near vacuum controlled atmospheres, occurs in a chamber that is first evacuated and thereafter partially pressurized with small amounts of gas to create a minute partial atmosphere of desired composition. Multiple operations are commonly achieved with a single pump down or initial evacuation of a multiple stage, valved chamber by evacuating the chamber initially and then repressurizing to the desired partial atmosphere and reevacuating the chamber during each movement of work between stations as different coatings are applied at successive positions within a single sputtering device.
Typical of such devices is the continuous vapor deposition system of U.S. Pat. No. 5,016,562 wherein a series of modules are separated by valves and each deposition module is preceded and succeeded by an isolation module in addition to the entrance and exit load lock modules. U.S. Pat. No. 4,048,955 illustrates a vapor deposition mechanism wherein a series of processing cells or chambers are separated and isolated by above atmospheric nitrogen seals to exclude the ambient outside atmosphere.
Current rigid disk sputtering machine designs have evolved from semiconductor and thin film head applications with few modifications other than accommodating dual sided deposition. Also, system manufacturers, with limited experience or understanding with respect to thin film disks, have provided machines with overly complex designs in order to accommodate options such as substrate biasing, RF etching and RF sputtering. This complexity adds not only to initial cost, but also adds ongoing maintenance cost and reduced reliability. These sputter system manufacturers attempt to make their machines more versatile to broaden the market base by including features such as isolated process chambers, repetitive pump down to high vacuum and product versatility.